1. Field of the Invention
The present invention relates to an injectable composition of piroxicam potassium. More particularly, the present invention relates to a stable and painless injectable composition of piroxicam potassium which contains piroxicam potassium, triethylene glycol, lidocaine and distilled water for injection.
2. Background Art
Piroxicam is a non-steroidal antiinflammatory agent belonging to a group of benzothiazine derivatives and shows antiinflammatory, analgesic and antipyretic activities through the inhibition of prostaglandin synthesis. Further, piroxicam has a prolonged plasma half-life and therefore exhibits sufficient effect only by the administration of a daily dose once a day. However, when piroxicam is administered per oral, it shows undesirable side effects such as upper abdominal pain, dyspepsia, facial edema, etc. Accordingly, an injectable preparation of piroxicam has recently been developed and used in the clinical field. However, since piroxicam itself is sparingly soluble in water, when piroxicam is prepared and stored in the form of an injectable preparation, this preparation may readily become turbid and piroxicam may be precipitated out from the preparation. Accordingly, it has been strongly required to develop the means which can stabilize piroxicam without any influence on the pharmacological activities thereof and further reduce a pain as the main problem of an intramuscular injectable preparation.
The present inventor has extensively studied to develop such means and then identified that if piroxicam which is sparingly soluble in water is converted into its potassium salt, piroxicam potassium salt can be formulated into an injectable preparation. However, the present inventor has also indentified that the piroxicam potassium injectable preparation caused a severe pain, when it is injected, and is unstable and therefore also has some problems that piroxicam may be crystallized out from the preparation and the preparation may become turbid.
Thus, the present inventor has conducted repeated experiments on various combinations of conventional stabilizers, solvents and analgesics to find out the optimum combination of solvent, stabilizer and analgenics for improving the stability of injectable piroxicam preparation and reducing the pain which may be caused by injection of the preparation. As a result, the present inventor has identified that in piroxican potassium-containing injectable solution triethylene glycol is the best solvent and stabilizer and lidocaine which is a local anesthetic can display only the desired analgesic activity without any undesirable side effect and interactions with other ingredients and thus completed the present invention.
Therefore, it is an object of the present invention to provide a stable, painless piroxicam potassium injectable composition.
It is a further object of the present invention to provide a stable and painless injectable composition of piroxicam potassium which contains piroxicam potassium as an active ingredient, triethylene glycol as a solvent and stabilizer, lidocaine as an analgesic and distilled water for injection.
The more pertinent and important features of the present invention have been outlined above in order that the detailed disclosure of the invention which follows will be better understood and that the present contribution to the art can be fully appreciated. Those skilled in the art can appreciate that the conception and the specific embodiment disclosed herein may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. Further, those skilled in the art can realize that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the claims.